The manufacture of earth colours
CHAPTER VI
RED EARTH COLOURS 151 Bole 152 Native Ferric Oxide as a Pigment 154 Iron Glance 154 Hematite 155 Raddle 155 Burnt Ferric Oxide and Ochres 158 (_a_) Burning in the Muffle 158 (_b_) Caput Mortuum, Colcothar 160 (_c_) Calcining Ferric Oxide 161 Ferric Oxide Pigments from Alum Sludge 164